Secondary clock.



A. L. SOHM.

SECONDARY CLOCK.

APPLICATION man MAYZI. 1911.

Patented May 6, 1919.

Witnesses UNITED STATES PATENT OFFICE.

ALFRED L. SOHM, OF CHICAGO, ILLINOIS, ASSIGNOR TO SOHM ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

sncommmz oLocK.

Specification of Letters Patent.

Patented May 6, 1919.

To all whom it may concern Be it known that I, ALFRED L. SoHM, a citizen of the United States, residingat Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Secondary Clocks, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

My invention relates to secondary clocks.

It is an object of the present invention to provide a step-by-step mechanism which is simple and positive in operation and which automatically locks against false operation.

It is a further object to provide means for unlocking the step-by-step mechanism manually when it is desired to set the same.

A still further object of the invention is to provide an improved and simplified secondary clock.

In the accompanying drawings, I have shown my invention as embodiedin a secondary clock, but it is obvious that the stepby-step mechanism therein shown is capable of wider application than the particular mechanism in which I have illustrated the same. 9

Figure 1 is an elevationalview of the sec-- ondary clock embodying the principles of my invention, some of the parts being shown in section to more clearly reveal the struc-- ture .7, 7, these studs being fastened'to the top.

and lower portions of a plate 8.- This plate has mounted thereon a second plate 9, having an offset portion 10, so as to provide a space 11. The late 8 carries electromagnets 12, 12, whlch are preferably secured by means of screw: passing into the cores Fig. 2 is a view looking at the mechanism- 13, 13. At the rear of these electromagnets, the cores 13, 13 are passed through a supporting member 14. Supported in the plates 8 and 10, and in the member14, is a spindle 15, the left-hand portion of which is diminis'hed, and has a flat portion 16, so as to properly engage an enlargement of the minute hand 16. A nut 17 serves to maintain the minute hand in position upon the spindle. This spindlecarries a pinion 18, which meshes with the gear 19, to which is secured a pinion 20, which meshes with a gear '21, mounted'upon a tapered sleeve 22,

rotatably mounted upon the spindle 15. The hour hand 23 has a 'hub portion 24, which is in frictional engagement with the sleeve 22. As is shown particularly in Fig. 1, the gear 19 and the pinion 20 are loosely mounted upon a pin 25, extending from the plate 10. The ratio of the pinions and gears is such that the minute hand will make twelve revolutions, while the hour hand makes but one. In order to advance both of these hands at the proper time, I have an arrangement in the form of a disk 26, which is secured upon the spindle 15, and occupies the space 11 betweenthe plates'8 and 10, and, as is shown in Fig. 2, is provided with a plurality of circular openings 27. There are preferably sixty of these openings, and they are disposed concentrically with the spindle 15. The disk, and the parts thereon, are held in a locked-position by means of a locking stud 28, the right-hand end of which is rounded so as to be readily forced into any one of the openings 27, when said opening is in alinement therewith. It will be noted that each of the openings 27 is countersunk on both faces of the disk 26. The stud 28 is "slidable in a sleeve 29 secured in the plate 10 andhas a groove 30, which is engaged by the fingers 31 of the spring 32. whose lower end is bifurcated, at 33. and secured by means of pins 34 to the plate 10.

The supporting member 14 has two lugs, 35. 35 for pivotally mounting the armature v36, the lower end of which has a'tongue 37 which normally bears against a tongue 38 onthe supporting member 14. The armature has an extension 39 which terminatesin'a circular pin portion 40, which passes through an opening in the disk rotating arm 41, thus forming a swivel joint. A pin 42 serves to maintain the arm 41 in position. The arm 41 has a lug 43 to which is secured The forward end of the arm 41 is in the" form .of a pin 46, .whose end is rounded so as readily to engage in any one of the openings 27, which may be in alinementthere-r.

with. Normally, this pin portion is held against; one end of an :opening, 47 occurringv in thezplatea8, byimeansofithe-spring The ielec'tromagnetsalQ, 12 are=provided -J with" suitable,tenminalsyonly one of which is shown, :which arexconnected to a circuit including-a suitable source of power. This circuit, 1 rit will: the understood, 1 includes-a masterf-clockvzwhosei operation determines.

the: :energtizatiom of the electromagnetsand consequently the: advancement of the minute 1 and hour-hands. WVhen. such energization is efiec't'ed,ithe armature 36: is attracted,'thus causing forward r advaneement i of the "disk rotating arm 41.7 Thereupon,-the roundedportion 46 engages: the stud 128, and a forces it out of-theopening in the' diskwhich it engages at tl13;t"!tiln8.'m' This part of the movement 0fthe armflunlocksxthe disk in orderll-thatit mayzzbefadvanced in a clock' WISE directiom The COIlOlLlCllIlg movement of the" 'arm141 bringsdhei cam 1 portion 48 ment sufiicient to throw the locking stud 28 into and out of locking position. A cam and is adapted'for engagement underneath -vention is the-fact Ithattherdisk 26.niaybe:

.the ,springi32 when the member 50 is rotated to its active position, so that the finger piece 52 occupies the right-hand end ofthe 'portion 55 is provided upon the'member '50 slot 58, thereby withdrawing the stud 28 from'the" 013611i11guWl'1iCh it engages at that time. The disk 26 is thus unlocked and the set thetclock, after whichwtheomember 5O minute and hour hands maybe revolvedato,

maybe rotated backto its normal position, whereby: locking of the3'diskr26-is again ef- 'fected; =i

By means of ithemechanism embodying; my

invention, a quick and positiveaction: of the advancement of the minuteland.hounhands 1s securedpin addition to locking them 1nposition after each advancenientyand the clock is thereby*maintained in isynchronismwith a master-clock, whichdetermines the energia zation of the electromagnetgs '1' One: of the important featuresof my ina manually unlocked by meansofthei readily E accessible unlocking. device -disposed"so as to be manually operated-withoutdisturbing.

the adjustment-of any Of the: parts. iaThis has its advantage'in the fact that illGi'GlOCk army he completely installed andthem-set: a against: the"- rounded stud: 49 carried by the .in sy hronism with the imastereclock: with plat-e S, and,'-"since.the' pinportion 46 has v1 forced the stud 28 out: of the -opening, the

tion of the electromagnets 12, the spring 44 will draw the armba'ck into its normal p0- sition, as shown in Fig? 3'. It willbe seen that the"--advancing; action and the subsequent locking of the disk 26 is positive,

and," further,that during such advance-- ment there is practically no friction ofi'ered' by the stud, owing to the conformation of its end, and: also to the factthat the open ings 27 are -c0unter'sunk.'=

In setting the clock after ithas been in stalled, it is desirablethat'.easilyaccessible means be provided ior unlocking the'disk in order that 'the =hand s may be rotated. To" this-"endgrI' have== provided a disk unlocking member" 50 pivo-ted -at 515 to the-plate 10.

' be made without departin'g the'least amount of Work- 41.

WVhile I have herein showni and described 1 certain features of my invention, -I do not wish to be limited" to the iprecise arrange- 1 .ment: sl1own,3since.it is apparent to thosem skilled in the art, that modifications may a romtherspirit and scope'of my invention. a"

What I" claim as new 1 anddesire to secure by Letters Patent is i 1. In a secondary clock, a rotatable stepby-step disk having" a concentricfiseriesof through holes, a spring pressed locking pin adapted to enter said holes'tofhold'the disktl':

- against rotation ia magnetically movable member on the opposite side of the disk hav This inember 6 0 has fingeri52 extendingthrough; slot 53 i'n the'dial 6, this slot, of coursarabeingigconcentric with the pivot point 51. The, member: 5-0'ihasan opening 54 throughv which? the .sleevea 29 projects.

The opening -.54ra11@ws-\0 a range of move-a ing a free end 1 adapted to enter 5 said holes and push said locking pin out to unlock the: disk, and means for moving said free end; of

the member after *the :diskz-i's unlocked; to

rotate said disk a definite distance-2 i 2. In'a secondary cloc'k,= a rotatable 'step I by-step disk, having "circumferential series of holes, a spring pressed locking pin enterf ing said holes-.i'rom oneside -of the'diskpa 1 spring held 5 longitudinally :unovablef disk actuating memiber, electromagnetic ameans for actuating said memberg-a projectiona'on said member adapted to enterisaid holes and push sa-id locking @pin: :out; icam means? '011'3- said 'member anducooperating i fixed :camw

means for forcing the said end of said meme-r berv :transversely against the i a action rof. its

holding spring after it has unlocked the disk to rotate the disk a predetermined amount.

3. In a secondary clock, a step-by-step rotatable disk having a circumferential series of holes, a spring pressed locking pin entering said holes to lock the disk against rotation, and an electromagnetically operated armature movable back and forth relatively to said disk, a spring held disk actuating member having one end pivotally connected to said armature for movement toward and from the disk, a fixed member havin a guide slot in which the free end of said isk actuating member is transversely guided, the free end of said actuating member being adapted to enter said holes in the disk to engage the locking pin and push it out, and cam means for causing a transverse movement of said free end of said actuating port and adapted to enter said holes to lock the disk, said dial having a slot, cam means on said support for withdrawing said pin against the action of its spring, and a projection on said cam means extending through said slot in the dial for manually moving said cam into and out of active position.

In witness whereof, I hereunto subscribe my name this 17th day of May A. D. 1917.

ALFRED L. SOHM.

Copies of this patent may ho obtsinod or two cents esoh, by addressing tho "Commissioner of l'ntents, Washington, D. 0. 

